Correlations of Precipitation and Temperature with Spring, Regrowth, and Mature Crested Wheatgrass Yields

Abstract

Yields of crested wheatgrass on August 1 and May 15 and its August 1st regrowth, with or without N fertilizer, were correlated with 45 temperature and precipitation variates. Correlation coefficients for mature yields with monthly precipitation were highest for combinations of eight or more consecutive months, beginning the previous July, August, or September. The inclusion of growing season temperature increased the coefficient of determination by a maximum of 8 percentage units. The best combination for predicting unfertilized mature yield was July- May precipitation plus mean March, April, and May temperatures and accounted for 64% of the total yield variation. Mean February temperature with March precipitation accounted for 83% of the variation in spring yield.